Plowshare is a set of command-line tools (written entirely in Bash shell
script) designed for managing file-sharing websites (aka Hosters).

Plowshare itself doesn't support any websites. It's just the core engine.
Support for websites are added via modules. They are available separately
and it's recommended to be installed by the user rather than system-wide.
It can be installed/updated by the user to ~/.config/plowshare/modules.d/
directory using:

$ plowmod --install
$ plowmod --update

However, if you'd like them system-wide, please see the plowshare-modules
SBo package. Modules will be installed to /usr/share/plowshare/modules/

Per INSTALL, either rhino or sunspider (the latter is not available on SBo)
are optional runtime dependencies. It is stated they are required for some
sites. However, I have not come across any that didn't work. Let me know
if it should become a required dependency.
